1. Field of the Invention
The present invention is directed to an extensible support structure particularly adapted for supporting a steering column in adjustable positions with respect to a vehicle frame.
2. Prior Art
In recent years, various proposals have been suggested for providing adjustable steering columns. For example, tiltable steering columns have been suggested to facilitate the entry of the driver to the driving seat. Other suggested structures include steering wheels which can be axially adjusted to enable the desired position of the steering wheel for a particular driver.
In the commercial vehicles, it is often desirable that the steering wheel and steering column remain in substantially the same orientation while being adjusted to various positions relative to the dashboard or frame structure. One method proposed for obtaining an incremental adjustment of the position the steering wheel and column while maintaining the desired orientation thereof is disclosed in the U.S. Pat. No. 3,678,778, which issued to Donald W. Groves on July 25, 1972.
In providing a device for adjusting the position of a steering column and wheel assembly relative to the dashboard, it is desirable to have a device which allows an infinite variation in the distance of the assembly from the dashboard within a prescribed range. It is also desirable to provide an extensible structure which is held in the desired position by a frictional locking mechanism which will yield under a predetermined force such as occurring during a collision of the vehicle.
In our above-mentioned application, we proposed a support structure which would enable infinite variations in the position of a steering column and wheel assembly relative to a structural member without varying the orientation of the steering column. While this support structure satisfied many of the problems existing with the prior known devices, its structure pointed out additional features which were desired.